Synthesis and biological evaluation of vanadium complexes as novel anti-tumor agents.

A class of vanadium complexes were prepared and investigated for their antiproliferative effects by MTT assay. The structure-activity relationship was extensively studied through the ligand variation. The results showed that the synthetic vanadium complexes demonstrated moderate to good antiproliferative activities against the four cancer cell lines including MGC803, EC109, MCF7 and HepG2, respectively. Of note was that most of the complexes showed preferential growth inhibitory activity to some degree toward gastric cancer line MGC803. Among them, complex 19 exhibited the most and broad-spectrum proliferative inhibition against the tested cell lines. In addition, mechanism studies illustrated that complex 19 could prevent the colony formation, migration and EMT process, as well as induce apoptosis of MGC803 cells. Furthermore, Western blot experiments revealed that the expression of apoptosis-related proteins changed, including up-regulation of Bax, PARP and caspase-3/9, as well as down-regulation of Bcl-2.